Ice Bock through MouseOver, possible ?

My ISboxer set up is almost finished. I even managed to mouseover heal from my tank ! A dream come true ! This repeater thing, what a nice feature ...

Now onto something more tricky :

On my 5-Mages team, I would like to be able to MouseOver on one of the Mages, and have her and her only bubble or IceBlock herself.

I thought passing a /cast [target=mouseover] Ice Block would work, and only the one being actually MouseOver'ed would Ice Block, but they end up all Ice Block'ing themselves (default behaviour for a self-only spell I guess).

Anything possible with macros, like adding some sort of condition ? Or perhaps with one of the addons used with clicking. Does HealBot handle IceBlock and other like spells ?

No big deal if this is not possible, I would revert to using 5 different keys then. It's just that the MouseOver solution would be so much more elegant.

I just have my party frames sorted alphabetically with the player included, and use the click cast option in Vuhdo.

The problem with target=mouseover, is the macro belongs to a specific toon, and iceblock is not targetable.
You could do Hand of Protection, as a pally since that is targetable.

The Vuhdo/Grid+Clique option on the party frame is probably the closest you'll get.
Unless you want a keybind for each.